ambiguity in the expression evaluation - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: HP Prime (/forum-5.html) +--- Thread: ambiguity in the expression evaluation (/thread-8185.html) ambiguity in the expression evaluation - compsystems - 04-17-2017 02:23 AM Hello, As we know, the variable X is a global variable for HOME / CAS that can not be deleted and can only contain a real number. an ambiguity in the expression evaluation, see following example I propose a solution inspired by MATLAB, declare symbolic variables Symbs A,...Z example X, unicode FF38 by modifying the text font (bold) to differentiate it from normal X The commands that throw symbolic expressions would use these variables and not the user variables ((X+2)*X+3)*X+4 ≠ ((X+2)*X+3)*X+4 HOME MODE (history) X:=0; [enter] v1:= [1,2,3,4]; [enter] "do you want to create a varible called v1" [ok] [enter] p1:=poly2symb(v1); -> ((X+2)*X+3)*X+4 // ok p1:=simplify(Ans(1)); -> 4 // ok or p1:=poly2symb(v1); -> ((X+2)*X+3)*X+4 // ok p1:=simplify([up][copy]); -> 4 // ok but p1:=simplify(poly2symb(v1)); // -> X^3+2*X^2+3*X+4, In this case the command "simplify" did not evaluate X, Why? v2:= [5,6,7,8]; [enter] p2:=simplify(poly2symb(v2)); // 5*X^3+6*X²+7*X+8 convolution:= p1*p2; -> (X^3+2*X^2+3*X+4)*(5*X^3+6*X^2+7*X+8) convolution:= simplify(Ans(1)); // 4 convolution:=simplify(p1*p2); // 5*X^6+16*X^5+34*X^4+60*X^3+61*X^2+52*X+32 convolution:=symb2poly(Ans(1)); // 4 convolution:=symb2poly(p1*p2); // [5,16,34,60,61,52,32]